The present invention is directed to a battery charger of one or more chargeable batteries. More particularly, the present invention is directed to a system and device for charging a plurality of batteries in which both the input voltage from a power source and the level of charge provided to the charging batteries can be monitored and the system shut down when pre-set charge levels are reached. The present invention further includes a device that provides a charging current having a periodic pulsed variable frequency component that maintains the condition of the charged battery plates thereby extending the life of the battery.
Increasingly, batteries are being employed in a wide variety of applications as a source of electrical energy. Along with the increasing use of batteries, recharging of those batteries as they become depleted has become also increasingly prevalent. Frequently, the recharging of depleted batteries involves use of a current source such as an electric outlet. In some instances, however, it is more convenient, if not necessary, to recharge the batteries from another battery that provides the required energy source. Typical of these situations are boats and mobile homes which may have multiple batteries for various appliances and equipment in addition to the main battery that is used to start the vehicles engines. Clearly, in such instances, it is critically important that the charging of the secondary batteries from the main battery be in a controlled manner that both provides an adequate charge to the secondary batteries and does not deplete the primary battery so that it can no longer perform vital function of starting the vehicle's engine.
There is, therefore, the need for a battery charging system which monitors the level of charge applied to secondary batteries as well as the level of charge of remaining in the main battery from which the charging current is drawn and shuts down the system if either of these levels is passed. There is a further need for a battery charging system that is capable of charging multiple batteries either in series or in separate circuits without a drop in voltage. Still a further need is for a battery charging system having the aforementioned features which is capable of extending the life of the batteries being recharged especially wet cells such as lead acid batteries which have plates.